如果可以用另一个辅助矩阵,那么解法就比较简单:
class Solution:
def rotate(self, matrix: List[List[int]]) -> None:
h = matrix.copy() #辅助矩阵,浅拷贝
rows = len(matrix)
cols = len(matrix[0])
for i in range(cols):
tmp = []
for j in range(rows-1,-1,-1):
tmp.append(h[j][i])
matrix[i] = tmp
return matrix
但是这题不可以
可以总结出一定的规律,首先,可以把矩阵翻转,再把对角交换
class Solution:
def rotate(self, matrix: List[List[int]]) -> None:
"""
Do not return anything, modify matrix in-place instead.
"""
n = len(matrix)
# 矩阵垂直翻转
# matrix.reverse()
for i in range(n//2):
for j in range(n):
matrix[i][j], matrix[n-i-1][j] = matrix[n-i-1][j], matrix[i][j]
for i in range(n):
for j in range(i): ##对角交换
matrix[i][j],matrix[j][i] = matrix[j][i],matrix[i][j]
return matrix